Cartridge case

ABSTRACT

Pipe, casing, or the like having a fitting disposed at one end thereof. The fitting has an internal and an external section which are connected in a form-locking manner, and the end of the pipe, casing, or the like is held therebetween by means of a form-locking and/or frictional connection. In particular, the external section annularly surrounds the internal section and can be connected with the internal section by means of a snap connection, and at least one of the sections is made of a sufficiently elastic material. When used as a shot cartridge case, the internal section is provided with a primer cap support and an axial flash hole.

United States Patent Schnitzer Sept. 12, 1972 [54] CARTRIDGE CASE 3,435,765 4/1969 Gawlick ..102/43 P Inventor: Oskar Schnitzer, Lehmusstrass 38, P Furth/Bay, Germany 1,113,479 11/1954 France ..102/44 1,181,667 1/1959 France ..102/44 [22] Filed: Jan. 23, 1970 487,320 6/ 1938 Great Britain ..102/44 [21] PP NOJ 5,287 1,420,080 10/1965 France ..102/43 P Primary Examiner-Robert F. Stahl [30] Foreign Application Priority Data Attorney-Craig and Antonelli F 1). 1,1969 G ..P1 05 e ermany 9 103 7 ABSTRACT R, Pipe casing or the having a at [5 Cl- ..F42b one end thcreofi The fitting has an internal and an ex- Fleld of Search ..102/44, 43, P, F temal section are connected in a formJoeking manner, and the end of the pipe, casing, or the like is [56] References Cted held therebetween by means of a form-locking and/0r UNITED STATES PATENTS frictional connection. In particular, the external sectron annularly surrounds the internal sectlon and can Jackson be connected the internal ection means of a Potts nap connection and at least one of the ections is 2,823,611 2/1958 Thayer ..102/44 made of a sufficiently elastic material w d as a 498,857 6/ 1893 Overbaugh ..102/44 Shot cartridge case, the internal Section is provided 662,137 11/1900 Tellerson 102/44 with a primer cap support and an axial flash hole. 2,902,934 9/ 1 959 Louis 102/43 3,026,802 3/1962 Barnet et a1. ..102/44 27 Claims, 2 Drawing Figures PATENTEUSP12|912 3.690.256

INVENTOR OSKAR SCHNITZER BYW/WLMQW ATTORNEYS CARTRIDGE CASE BACKGROUND OF THE INVENTION the like with a fitting disposed at one end, which has an internal and an external section.

It is conventional in shot cartridge cases to provide, at one end of the case which is manufactured, for example, for cardboard or stain-hardened plastic, a twopiece fitting comprising an internal bottom plug, insert piece, or the like, of, for example, cardboard or plastic, and an external metal cap. These two sections are joined to the end of the case by radially compressing the metal cap by means of a suitable tool after the case and the bottom plug have been introduced therein, so that the case is held between the metal cap and the bottom plug by frictional contact. Depending upon the requirements, it is also possible to provide the metal cap, either additionally or by itself, with one or several indentations,corrugations, or the like extending in the circumferential direction, so that a shape-mating or form-locking connection is established between the metal cap and the case end. This type of connection between the case end and the fitting,however, has the substantial disadvantage that the manufacturing expenses are rather substantial in order to obtain a strength of the connection satisfying all requirements.

Although it is further known to produce pipes, casings, or the like integrally with a fitting provided at one end, for example to mold the same from plastic, this manufacturing method cannot be employed when widely varying requirements must be met, e.g., from a mechanical point of view, by the pipe, the casing, or the like, and the fitting. Thus, it has been impossible heretofore, e.g., in the production of integrally manufactured completely plastic shot cartridge cases, to reliably prevent undesired crack formations furing firing at the seal or closure of the front end of the case, due to an insufficient mechanical strength of the case shank.

SUMMARY OF THE INVENTION It is the aim of the present invention to overcome the above-mentioned disadvantages in connection with the example of shot cartridge case. In particular, it is a main aim of the present invention to simplify the manufacture of the connection between the pipe, the casing, or the like, and the fitting, with the strength of the connection remaining at least as satisfactory.

The underlying problems are solved in accordance with the present invention by connecting the two sections of the fitting in a shape-matting or form-locking manner, and by holding the end of the pipe, the casing, or the like, therebetween by means of shape-mating and/or frictional contact. If, in this connection, the shape-mating junction between the two sections of the fitting is constructed, for example, in the manner of a screw connection, it is possible to vary in a simple way the strength of the connection by threadingly engaging the two sections of the fitting to a greater or lesser extent.

To attain a simple assembly of the individual parts, which is thus as economical as possible, it is advantageous to provide in a suitable embodiment of the present invention that the external section of the fitting annularly surrounds the internal section thereof and can be connected with the internal section in the manner of a snap connection. In this connection, at

.least one of the sections is made of a sufficiently elastic material.

For the purpose of obtaining as great a strength as possible of the coupling between the pipe, the casing, or the like and the fitting, on the one hand, with as favorable a stress distribution as possible in the pipe, the casing, or the like,- on.the other hand, it proves advantageous in accordance with a further suggestion of the present invention to fashion the two sections of the fitting and one end of the pipe, the casing, or the like, in the zone of the shape-mating and/or frictional connection, substantially with truncated cone surfaces having a generating angle of about 45.

The connection can be still further improved by providing, according to a further suggestion of the present invention, at least one of the sections of the fitting, in the zone of theshape-mating and/or frictional connection, with fine .grooves, serrations, or the like extendingin theperipheral direction of the pipe, the casing, or the like. If both sections of the fitting are provided withsuch a surface shape, it is, of course, necessary to make sure that the grooves, serrations, or the like are arranged and constructed in both sections so that weakening or even severing of the material of the pipe, the casing, or the like is reliably avoided under all circumstances.

The above-described invention, which can be employed, for example, for sealing one end of plastic casings, e.g., for blasting cartridges, can be used particularly advantageously in all cases where widely varying requirements must be met by the properties of the pipe, the casing, or the like, on the one hand, and the properties of the fitting, on the other hand, such as, for example, in the use as a shot cartridge case wherein the internal section of the fitting is formed with a primer support and an axial flash hole. Here, it is possible to select for the case shank a tough and high-strength plastic, e.g., strain-hardened low-pressure polyethylene, and for the external fitting section with the groove for the extractor of the firearm, as hard a plastic as possible, for example a polyamide or a polycarbonate.

BRIEF DESCRIPTION OF THE DRAWING These and further features, advantages and objects of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, an embodiment of the present invention, and wherein:

FIG. 1 is a cross-sectional view of the individual components of the shot cartridge case prior to assembly;

and

FIG. 2 is a cross-sectional view of the finished shot cartridge case.

DETAILED DESCRIPTION OF THE DRAWING Referring now to the drawings and, in particular, to FIG. 1, the case 1 is made, for example, of strainhardened low-pressure polyethylene and is tapered at the end 2 into a truncated cone having a generating angle of about 45. From the other end, the internal section 3 of the fitting is inserted in the case 1, namely with the end having the annular head 6. At the other end, the internal section 3 is provided with an annular, cylindrical extension 7 serving for receiving the propellant charge and resulting in a reinforcement of the shot cartridge case and an improvement in the ignition and conversion of the propellant charge. The internal section 3 is further provided with the bearing portion 8 for receiving the primer cap 9 and with the axial flash hole 10.

The section 3 is passed in the direction of arrow A with the annular bead 6 through the end 2 of the case 1, optionally with appropriately widening the latter elastically, and is pressed into the external, essentially annular section 4 of the fitting to such an extent until the annular bead 6, under corresponding elastic deformation of one or optionally also both sections of the fitting, snaps into the corresponding annular shoulder 11 formed in section 4. This snap connection between sections 3 and 4 is constructed so that the end 2 of the case 1 is sufficiently firmly clamped between the sections 3 and 4 and is thus held securely by means of frictional contact and, when the material of the case 1 is sufficiently structurally rigid, also by means of shape-mating or form-locking connection.

An additional increase in the strength of the connection is effected by the grooves in section 4, extending in the peripheral direction, the dimensions of which are, of course, selected in such a manner, in dependence on the material of the case, that optimum conditions are achieved with respect to the strength of the coupling. Since the section 3 is elastically compressed when being pushed into the section 4, the primer cap 9 is suitably inserted in the section 3 only when this section is already in shape-mating or form-locking connection with section 4.

The assembled shot cartridge is illustrated in FIG. 2, wherein the parts identical to those in FIG. I bear the same reference numerals. The cartridge has propellant charge 12 within the annular cylindrical extension 7 of the section 3. This propellant charge is covered toward the front end 14 of the case by means of the interposed element 13 made, for example, of felt or cardboard, and resting on the extension 7. The shot charge is disposed between element 13 and the front end 14 of the case, which is closed off, for example, by folding, in a conventional manner.

The primer cap 9 inserted in the support 8 presses the internal section 3 more or less strongly against the external section 4, depending on the dimensions of the primer cap as related to those of the support 8, and thus prevents an unintended detachment of the shape-mating and/or frictional connection of the pipe, the case 1 or the like with the fitting, even, for example, when one of the two sections of the fitting should be subjected to a minor plastic deformation during the assembly, which could entail, if the primer cap 9 were not inserted subsequently, under certain circumstances, an undersired reduction of the contact pressure between the two sections of the fitting. Furthermore, the pressure of the propellant gases forming after ignition is effective along the same lines, i.e., supporting the shape-mating and/or frictional connection.

While I have shown and described only one embodiment in accordance with the present invention, it is to be clearly understood that the same is susceptible to numerous changes and modifications as will be apparent to a person having ordinary skill in the art, and I, therefore, do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications within the scope of the present invention.

I claim:

1. A casing comprising a hollow elongated casing portion having an inwardly diverging open end portion with a passageway communicating with the hollow interior of the remainder of said casing portion, and a fitting means for securing said casing portion arranged at the open end portion of said casing portion, said fitting means including an internal section, at least a portion of which is constructed to abut the interior of said casing portion and another portion of which extends through the passageway in said open end portion, and a separate external section, at least a portion of which is constructed to abut the exterior of the open end portion of said casing portion and another portion of which abuts the portion of the inner section extending through the passageway, said internal and external sections having means for operatively joining said sections in the manner of a snap connection, at least one of said sections having at least an elastic portion constructed to be temporarily deformed in forming said snap connection and to spring back to a substantially undeformed state upon completion of the formation of said snap connection.

2. Casing according to claim 1, wherein the end of the casing is operatively held between the internal and external sections by a form-locking connection.

3. Casing according to claim 2, wherein the internal and external section and the end of the pipe are formed, in the zone of the form-locking connection, substantially with truncated cone surfaces having a generating angle of about 45 with respect to a longitudinal axis of the casing.

4. Casing according to claim 3, wherein the external section substantially annularly surrounds the internal section.

5. Casing according to claim 2, wherein, in the zone of the form-locking connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.

6. Casing according to claim 5, wherein the external section substantially annularly surrounds the internal section.

7. Casing according to claim 6, wherein the internal and external sections and the end of the pipe are formed, in the zone of the form-locking connection, substantially with truncated cone surfaces having a generating angle of about 45 with respect to a longitudinal axis of the casing.

8. Casing according to claim 2, wherein the casing is a shot cartridge case, and the internal section is provided with primer cap support means and a substantially axial flash hole.

9. Casing according to claim 8, wherein the internal and external sections and the end of the pipe are formed, in the zone of the form-locking connection, substantially with truncated cone surfaces having a generating angle of about 45 with respect to a longitudinal axis of the casing.

10. Casing according to claim 9, wherein the external section substantially annularly surrounds the internal section.

ll. Casing according to claim 10, wherein, in the zone of the form-locking connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.

, l2. Casing. according to claim 1, wherein the end of the casing is operatively held between the internal and external sections by a frictional connection.

13. Casing according to claim 12, wherein the internal and external sections and the end of the pipe are formed, in the zone of the frictional connection, substantially with truncated cone surfaces having a generating angle of about 45 with respect to a longitudinal axis of the casing.

14. Casing according to claim 13, wherein the external section substantially annularly surrounds the internal section.

l5. Casing according to claim 12, wherein, in the zone of the frictional connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.

l6. Casing according to claim 15, wherein, in the zone of the frictional connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.

17. Casing according to claim 15, wherein the internal and-external sections and the end of the pipe are formed, in the zone of the frictional connection, substantially with truncated cone surfaces having a generating angle of about 45 with respect to a longitudinal axis of the casing.

l8. Casing according to claim 17, wherein the external section substantially annularly surrounds the internal section.

19. Casing according to claim 12, wherein the casing is a shot cartridge case, and the internal section is provided with primer cap support means and a substantially axial flash hole.

20. Casing according to claim 19, wherein the external section substantially annularly surrounds the internal section.

21. Casing according to claim 20, wherein the internal and external sections and the-end of the pipe are formed, in the zone of the frictional connection, substantially with truncated cone surfaces having a generating angle of about 45 with respect to a longitudinal axis of the casing.

22. Casing according to claim 1, wherein the external section substantially annularly surrounds the internal section.

23. Casing according to claim 22, wherein the end of the casing is operatively held between the internal and external sections by a form-locking connection.

24. Casing according to claim 22, wherein the end of the casing is operatively held between the internal and external sections by a frictional connection.

25. Casing according to claim 1, wherein the end of the casing is operatively held between the internal and external sections by form-locking and frictional connections.

26. A shot cartridge casing comprising a hollow cylindrical casing portion having a substantially truncated conical end with a passageway communicating with the hollow interior of the remainder of said casing portion, and a fitting means for securing said casing portion arranged at the truncated conical end of said casing portion, said fitting means including an internal section having a ollow interior for receiving a primer cap and for providing an axial flash hole, a portion of the exterior of said internal section arranged in abutting relation to the interior of said casing portion and the remaining portion of the exterior of said internal section adapted to extend through the passageway in said truncated conical end of said casing portion, and an external section annularly surrounding and frictionally contacting said truncated conical end of said casing portion and the portion of said internal section extending therethrough, said internal and external sections being operatively joined in the manner of a snap connection, at least one of said sections having at least an elastic portion constructed to be temporarily deformed in forming said snap connection and to spring back to a substantially undeformed state upon completion of the formation of said snap connection.

27. A casing according to claim 26, wherein the external portion of said internal section extending through the passageway in said casingportion is elastic and provided with an expanded ridge which corresponds to a recess in said external section. 

1. A casing comprising a hollow elongated casing portion having an inwardly diverging open end portion with a passageway communicating with the hollow interior of the remainder of said casing portion, and a fitting means for securing said casing portion arranged at the open end portion of said casing portion, said fitting means including an internal section, at least a portion of which is constructed to abut the interior of said casiNg portion and another portion of which extends through the passageway in said open end portion, and a separate external section, at least a portion of which is constructed to abut the exterior of the open end portion of said casing portion and another portion of which abuts the portion of the inner section extending through the passageway, said internal and external sections having means for operatively joining said sections in the manner of a snap connection, at least one of said sections having at least an elastic portion constructed to be temporarily deformed in forming said snap connection and to spring back to a substantially undeformed state upon completion of the formation of said snap connection.
 2. Casing according to claim 1, wherein the end of the casing is operatively held between the internal and external sections by a form-locking connection.
 3. Casing according to claim 2, wherein the internal and external section and the end of the pipe are formed, in the zone of the form-locking connection, substantially with truncated cone surfaces having a generating angle of about 45* with respect to a longitudinal axis of the casing.
 4. Casing according to claim 3, wherein the external section substantially annularly surrounds the internal section.
 5. Casing according to claim 2, wherein, in the zone of the form-locking connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.
 6. Casing according to claim 5, wherein the external section substantially annularly surrounds the internal section.
 7. Casing according to claim 6, wherein the internal and external sections and the end of the pipe are formed, in the zone of the form-locking connection, substantially with truncated cone surfaces having a generating angle of about 45* with respect to a longitudinal axis of the casing.
 8. Casing according to claim 2, wherein the casing is a shot cartridge case, and the internal section is provided with primer cap support means and a substantially axial flash hole.
 9. Casing according to claim 8, wherein the internal and external sections and the end of the pipe are formed, in the zone of the form-locking connection, substantially with truncated cone surfaces having a generating angle of about 45* with respect to a longitudinal axis of the casing.
 10. Casing according to claim 9, wherein the external section substantially annularly surrounds the internal section.
 11. Casing according to claim 10, wherein, in the zone of the form-locking connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.
 12. Casing according to claim 1, wherein the end of the casing is operatively held between the internal and external sections by a frictional connection.
 13. Casing according to claim 12, wherein the internal and external sections and the end of the pipe are formed, in the zone of the frictional connection, substantially with truncated cone surfaces having a generating angle of about 45* with respect to a longitudinal axis of the casing.
 14. Casing according to claim 13, wherein the external section substantially annularly surrounds the internal section.
 15. Casing according to claim 12, wherein, in the zone of the frictional connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.
 16. Casing according to claim 15, wherein, in the zone of the frictional connection, at least one of the sections is provided with groove means extending substantially in the peripheral direction of the pipe.
 17. Casing according to claim 15, wherein the internal and external sections and the end of the pipe are formed, in the zone of the frictional connection, substantially with truncated cone surfaces having a generating angle of about 45* with respect to a longitudinal axis of the casing.
 18. Casing according to claim 17, wherein the external section substantially annularly surrounds the internal section.
 19. Casing according to claim 12, wherein the casing is a shot cartridge case, and the internal section is provided with primer cap support means and a substantially axial flash hole.
 20. Casing according to claim 19, wherein the external section substantially annularly surrounds the internal section.
 21. Casing according to claim 20, wherein the internal and external sections and the end of the pipe are formed, in the zone of the frictional connection, substantially with truncated cone surfaces having a generating angle of about 45* with respect to a longitudinal axis of the casing.
 22. Casing according to claim 1, wherein the external section substantially annularly surrounds the internal section.
 23. Casing according to claim 22, wherein the end of the casing is operatively held between the internal and external sections by a form-locking connection.
 24. Casing according to claim 22, wherein the end of the casing is operatively held between the internal and external sections by a frictional connection.
 25. Casing according to claim 1, wherein the end of the casing is operatively held between the internal and external sections by form-locking and frictional connections.
 26. A shot cartridge casing comprising a hollow cylindrical casing portion having a substantially truncated conical end with a passageway communicating with the hollow interior of the remainder of said casing portion, and a fitting means for securing said casing portion arranged at the truncated conical end of said casing portion, said fitting means including an internal section having a hollow interior for receiving a primer cap and for providing an axial flash hole, a portion of the exterior of said internal section arranged in abutting relation to the interior of said casing portion and the remaining portion of the exterior of said internal section adapted to extend through the passageway in said truncated conical end of said casing portion, and an external section annularly surrounding and frictionally contacting said truncated conical end of said casing portion and the portion of said internal section extending therethrough, said internal and external sections being operatively joined in the manner of a snap connection, at least one of said sections having at least an elastic portion constructed to be temporarily deformed in forming said snap connection and to spring back to a substantially undeformed state upon completion of the formation of said snap connection.
 27. A casing according to claim 26, wherein the external portion of said internal section extending through the passageway in said casing portion is elastic and provided with an expanded ridge which corresponds to a recess in said external section. 